11171721 has 32 divisors (see below), whose sum is σ = 17418240. Its totient is φ = 6300800.

The previous prime is 11171683. The next prime is 11171729. The reversal of 11171721 is 12717111.

It is not a de Polignac number, because 11171721 - 2¹⁰ = 11170697 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (11171729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 30940 + ... + 31298.

It is an arithmetic number, because the mean of its divisors is an integer number (544320).

Almost surely, 2^11171721 is an apocalyptic number.

11171721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11171721 is a deficient number, since it is larger than the sum of its proper divisors (6246519).

11171721 is a wasteful number, since it uses less digits than its factorization.

11171721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 437.

The product of its digits is 98, while the sum is 21.

The square root of 11171721 is about 3342.4124521070. The cubic root of 11171721 is about 223.5493237286.

Adding to 11171721 its reverse (12717111), we get a palindrome (23888832).

The spelling of 11171721 in words is "eleven million, one hundred seventy-one thousand, seven hundred twenty-one".